Protecting cream against oxidation



Patented Apr. 23, 1940 PROTECTING CREAM AGAINST QEA'I'ION Sidney Masher, New York, N. Y., assignor to Masher Foundation Incorporated, New York, N. Y., acorporation of New.York

No Drawing. Application July-19, 1939,

. Serial No. 285,354

6 Claims. (Cl. 99-163) This invention relates to improved methods for retarding oxidative deterioration and the development of oxidized, tallowy, metallic and "cardboard" flavors in cream and similar dairy compositions containing butterfat in the disconvors that is desired and the susceptibility of the tinuous phase and having the normal proportion cream to oxidation. of serum solids or milk solids not fat. It is important that the serum solids be added Cream normally contains between 30% and to normal cream since this process does not ap- 35% total fat in the discontinuous phase of the pear to be desirably carried out with cream conbutterfat emulsion and about 6% of serum taming a greater concentration of butterfat than 10 solids, these being primarily protein such as normal nor does it appear possible to carry out casein, milk sugar or lactose and some phosthis procedure with creams containing less than pholipin materials. the normal content of serum solids.

Ithas been found that the oil tastes and of! I It has been foun imp n t in liquid odors, such as flshiness, which develop readily dairy cream the proportion of butteriat should in cream are due primarily to the serum solids not be below about nor above about portion set forth above and particularly to the and the proportion of serum solids not below phospholipin portion. These materials in the about 5% nor above about 7.5%, and before the usual amounts in which they occur in cream apheat treatment, the amount of serum solids is depear to increase the tendency of the cream tosirably increased to about 8% or 9% and at go ward deterioration. 1 least 1% to 2% above and preferably 3% above An object of this invention is therefore to stathe normal serum solids content. bilize cream and similar dairy compositions in Example I I an inexpensive and readily acceptable manner and retard the development of tallowy, metallic, To cream 00111594111 butter! and 25 oxidized, fishy and other similar oil odors and e u ids was added 3 parts p million 1 g flavora CuSO4 and the cream divided into two lots as 7 Still further objects and advantages will apr6110! pear from the more detailed description set forth Cream Heated t0 5 n below, it being understood, however, that this Cream Treated with 211% of Powdered-1mm so m r t il degqflptlgn is given by way f 1 milk and then heated at 170 F. for 5 minutes. l tratio d explanation only, and t by way The creams were set aside at F. and tested of limitation, since various changes therein may for tfl-llowiness and deterifll'fltion at regular be made by those skilled in the art without de tervals with the followins results (the number of parting from the scope and spirit of the present $18118 indicating degree of e flm i n) 35 invention. i

In accordance with this invention. to cream Altercontaining its normal proportion of milk serum solids and its normal proportion of butter-fat, are animus 48hom's 721mm added relatively small proportions of concenp trated or preferably dried milk serum solids or OrcamA -Q. milk solids not fat followed by s heat treatment, 0mm i wi whereby the cream is materially stabilized 1 Egg: gfgizg i fgi gg gfi or serum Heat treatments of F. are insufllcient'to a solids apparently act to accelerate deteriora-' preferably be substantially above 145 F. and is carried out desirably at FL'to 180 F. or above fora period of' from 10' seconds to 15 minutes or more.

The serum solids are added in an amount varying from 1% to 15% against the butterfat weight of the cream, the amount added dependent upon the degree of protection against oxidized flashow the most desirable stabilizing action that is particularly observed at 155 F. and preferably at F. or above. Temperatures as high as 250 F. or higher even though for only minute fractions of a minute are satisfactory and are generally superior to longer holding periods at lower temperatures. T

In place of heating, or preferably in addition to the heat treatment, homogenization may also be resorted to in order to produce the stabilizing action. The more intimate contact of the fat globules with the increased serum solids at the temperature of activation results in marked stabilization.

Example II 30% butterf'at and 6% serum solids containing cream to which was added 8 p.p.m of

- was prepared as follows:

Cream A. Treated with 3.0% of powdered skim milk thoroughly admixed therein and then heated at 180 F. for 1 minute.

Cream 3. Heated at 180 F. for 1 minute an then thoroughly admixed with 3.0% of powdered skim milk.

The creams were tested as before:

Aim-

hours hours "hours CreamL :1: Cream]! :i:

It may be observed that where the heat treatment was given after addition of the serum solids a desirable improvement was observed, but

i where the heat treatment was given before the addition, deterioration took place rapidly.

Example II! To %butterfat containing cream contaminated with 3 p. p. m. of 011504 was added and .admixed therein 1.0% of powdered buttermilk and heated as follows:

Cream A. Heated at 145 F. for 30 minutes. Cream B. Heated at 170 F. forv 5 minutes. Cream'C. Heated at 200 F. for 30 seconds. The creams were examined with the following results:

Afteraihours labours 'nhours :i: :e :i:

The exact mechanism by which this invention is operative is not well understood. Although the added serum solids are water soluble and remain substantially in the water phase, nevertheless the fat of the cream is protected I against deterioration.

This is in direct contradistinction to the generally accepted factthat the availability and effectiveness of an antioxidant is dependent upon how thoroughly it is dispersed throughout the body of the fat or oil subject to oxidation where- I as, in accordance with this invention, the milkv serum solids are dispersed throughout the aqueous continuous phase to protect the discontinuous butterfat phase and are not dispersed throughout the discontinuous butterfat phase subject to oxidation.

In addition, whereas it is normally recognized that the milk serum solids appear to be responsible for the. development of fishiness and other oil flavors in milk, creamer butter, it is' necessary in accordance with this invention to add the serum portion to the cream and then to heat in order to retard this flshiness. Moreover, whereas lecithin, as one of the phosphatides that shows: antioxidant activity, is recognized as becoming inactivated as an antioxidant when heated to in excess M" C.,nevertheless the effectiveness of the serum solids containing phosphatides is only observed when they are added to the aqueous continuous phase of the cream and the cream then heated to a substantially elevated temperature.

Where the temperature is less than 145 1"., thereis substantially no improvement in keeping quality observed. The improvement istherefore not dependent upon reaching merely the melting point of the butteriat contained in the cream, for it is recognized that butterfat will normally melt at a temperature less than about F. and it requires a "temperature of approximately R'in order to show the desired antioxidant activity of the milk serum solids for addition to the cream subject to oxidation.

The cream that is treated in the aforesaid manner may be used for subsequent manufacture into powdered or liquid ice cream, sherbets, whipping cream, cream. cheese and other cheeses, powdered cream and other products derived from cream or made with the substantially stabilized cream and such products made with the sta-. bilized cream will themselves also be substantially stabilized against oxidative deterioration.

In addition, the cream that is thus treated may be frozen for storage and held for periods ranging up to 6 months to a. year or more at temperatures of 20 F. or below under which conditions the original fresh flavor of the cream will be substantially'retained and the development of tallowy and oxidized flavors will be very materially retarded.

Example IV 30% cream with 0% serum solids containing 3 p. p. m. of CuSOr was prepared as follows:

Cream A. Treated with 5.0% powdered skim milk thoroughly admixed therein and heated at F. for 2 minutes;

Cream B. Heated at 185 F. for 2 minutes and then treated with 5.0% powdered skim milk thoroughly admixed therein.

The cream was stored at 10 F. for 90 days and then used in the manufacture of strawberry ice cream. The degree of oxidized flavors observed with ice cream is given in the following table:

ice cream alter- 0 m 10 c 20 am Using cream A...;

i Usins mm B (inedl l0) Included in the serum solids that may be used in accordance with this invention are those comprising-powdered or concentrated skim milk and powdered or concentrated buttermilk, whey, and similar products derived substantially from milk serum solids. There may: also be included the lower fat containing milk serum materials such as partially skimmed powdered whole milk, etc. Although the substantially dried or dehydrated serum products are desirable for use, there may also be included the concentrated or evaporated milk products including concentrated or plastic buttermilk, condensed whey separator residue,

etc.

Extracts of these materials are also included such as particularly the alcohol soluble or water soluble extract or other extract using an OH solvent of a low molecular weight aliphatic group, or lactose (milk sugar), casein (milk protein), milk phospholipin, etc.

There may also be employed mixtures of lactose (milk sugar) and casein (milk protein), lactose and phosphatides such as lecithin, etc. These materials similarly require activation under conditions of heat.

Example V The cream used'in Example IV' was A. Treated with 2.0% of a mixture of equal parts of lactose and casein thoroughly admixed therein and heated to 190 1 for 15 seconds; and cooled.

B. Heated to 190 F. for 15 seconds, cooled, and then treated with 2.0% oi the mixture of lactose and casein thoroughly admixed therein.

tures made up of combinations of powdered skim milk with other products. For example, there may be utilized a mixture comprised of powdered skim milk, 5% lecithin and 5% dextrose, or a mixture comprising powdered skim milk and 15% lecithin, or a mixture comprising 98% powdered buttermilk and 2% tartaric acid.

Where lecithin is used with powdered skim milk, the addition 0! the lecithin can be made to the skim milk while in liquid condition and that mixture subjected to homogenization in order to thoroughly mix in the lecithin with the milk and then powdering the mixture. This homogenized lecithin mixture may be used for addition to cream'and then subjected to the elevated temperature to develop antioxygenicactivity.

Where the treated cream containing the heat reacted milk serum solids is to be used in the manufacture of an ice cream mix, it is desirable for the cream to be heated to a temperature 0! at least F. or higher prior to the addition of the sugar required in the ice cream mix in order to avoid excess carbonization or caramelization of the sugar. For example, in an ice cream mix where 10% of sugar is normally added, the milk serum solids may be added to the cream andthat, mixture heated to a temperature of, for example, 165 F. or higher, allowed to cool, and then such sugar, flavoring and other constituents may be added as normally used in the manufactured the ice cream mix.

Another method for the utilization of this invention is to separate ordinary milk into the cream and skim milk portion. The cream is then stabilized by adding to it a relatively small proportion of milk serum solids and then heated to an elevated temperature such as preferably to about 180 F. and, following this heat treatment, the cream is recombined with the skim milk in order to very materially improve the keeping quality of the recombined milk.

Example VI Milk containing 3.5% oi! butter-tat was separated into skim milk and a 85% buttteri'at cont ng cream. Before separating, the milk was co taminated by adding to it 3 p. p. m. of copper as copper sulphate. The separated skim milk portion was heated to 145 1". for 30 minutes and then cooled. To the separated cream portion was added 1.5% by weight of powdered skim milk. thoroughly mixed in the cream and then heated to 180 1''. for 5 minutes and cooled. The cream and skim milk were then recombined to reform the milk. The milk prepared in this manner was found to be substantially stabilized against oxidative deterioration and did not develop metallic, oxidized or tallowy flavors within a 72 hour Period. 7

, This treatment is particularly desirable in view of the fact that if ordinary whole milk were heat treated at 180 F., for example, for 5 minutes caramelization and scorching oi' the milk would result, whereas by separating the milk into its cream portion and skim milk portion, the cream may be treated in the aforesaid manner by adding to it a small proportion of serum solids, heating the cream to temperatures substantially in excess or that which would normally produce caramelization or the milk such as to about 180 F., heating the skim milk portion to temperatures under that of caramelization, such as to about 145 F. or below, and then recombining the cream and skim milk portions to obtain a milk that will be substantially stabilized against oxiwhat I velopment of tallowiness and oxidative deteriora:'

tion.

' 2. The process of stabilizing cream against oxidative deterioration, said cream containing about 30% to 35% butter-fat, said cream containing the normal proportion of serum solids to butteriat, which comprises adding to said cream about 3% of serum solids and dispersing said solids in said cream, and then heating the cream to about F. whereby there is produced a cream which will be highly resistant to the deveiopment of tallo'winess and oxidative deteriorations 3. The process of stabilizing cream against oxidative deterioration, said cream containing about 30% to 35% butterfat, said cream containing the normal proportions of serum solids to butteri'at, which comprises adding to said cream about 1% to 15% of serum solids, heating to substantially above 145 F. for a short period and then cooling, whereby there is produced a stabilized cream which will maintain a high score even when stored for a long period of time.

4. A stabilized cream, containing about 30% to 35% butteri'at, said cream being highly resistant to the development of oxidized tastes and flavors and resisting oxidative deterioration even when contaminated with copper sulphate, said cream containing the reaction product of between, about 1% to 15% of added milk serum solids over and above the normal milk serum solids content thereof, said reaction product having been formed by heating said milk serum dill solids with the cream at a temperature 0! 5etween about 145 F. and 170 F.

5. A dairy composition containing butteriat in the discontinuous phase and an aqueous medium in the continuous aqueous phase, said dairy composition being substantially stabilized against oxidative deterioration, said composition containing a small amount of. the reaction product 0! added milk serum solids, said reaction product 89 having been formed by heating the added milk serum solids with the dairy compodtion at a temperature above 145 F.

6. The process 01. stabilizing cream against oxidative deterioration, said cream containing the normal proportion of serum solids to butteriat, which comprises adding to said cream a small but substantial additional amount of concentrated serum solids and dispersing said solids in the aqueous phase of the cream, and then heating the cream to at least 145' 1". whereby there is produced a cream which will be highly resistant to the development of tallowiness and 10 oxidative deterioration.

SIDNEY MUSHER. 

